1. Field of the Invention
The invention relates to an impact damper assembly for an automobile, with an inner tube movably arranged inside an outer tube, wherein at least one tube is deformable by a relative displacement between the two tubes caused by an impact.
Such impact damper assemblies are employed in automobiles to convert the impact energy generated during a collision at least partially into deformation work. This arrangement minimizes damage to the automobile chassis, for example to the longitudinal chassis rails, and may even entirely prevent such damage at low speed. Damage to and deformation of the vehicle caused by a collision are reduced, which not only increases the safety for the vehicle occupants by maintaining the integrity of the passenger compartment, but also keeps the repair costs down. An insurer may also place the vehicle type in a more favorable insurance rating step.
2. Description of the Related Art
The patent AT 402 186 B already discloses an impact damper assembly with two tubes that are displaceable relative to each other, whereby an inner tube is arranged inside an outer tube. The inner tube and the outer tube each have a frusto-conical taper, wherein the frusto-conical taper of the outer tube encloses the frusto-conical taper of the inner tube. Moreover, the walls of the inner tube and the walls of the outer tube are approximately mutually parallel in the region of the frusto-conical taper. In the event of a vehicle collision, the inner tube is pushed into the outer tube and deformed so as to reduce the outside diameter of the inner tube. The impact energy is thereby converted into deformation work.
Disadvantageously with this arrangement, in particular the inner tubes tend to buckle or lock in the event of an impact from the side. Effective deformation work is then no longer produced and the impact energy directly causes deformation of the vehicle chassis, associated with substantial damage to the vehicle chassis, loss of safety, and increased repair costs. This performance has a negative impact when the damage class for this type of vehicle is set according to newer guidelines.
It is therefore an object of the invention to provide an impact damper assembly with two tubes, which are arranged inside one another for relative movement therebetween, wherein the impact damper assembly improves the rigidity for side impacts. The impact damper assembly should also produce sufficient deformation work in the event of a skewed impact to lessen the consequences of a vehicle collision and reduce, in particular, the repair costs and deformation of the vehicle chassis.